Corrugation-forming machines

ABSTRACT

A corrugation forming machine in which a sheet of material to be corrugated is passed between a pair of rollers having meshing gear-like teeth. Resilient means is provided either at the tip of a tooth or at the root between the adjacent teeth on the other roll with which the said tooth meshes, whereby each corrugation is pressed, as it is being formed, between the resilient means on one roll and a relatively non-resilient portion of the other of the rolls.

United States Patent Bemrose et al.

[451 Jan. 23, 1973 CORRUGATION-FORMING MACHINES inventors: Colin R. Bemrose; Dennis C. Brown; William G. Turner, Leamington Spa, England Associated Engineering Limited, Leamington Spa, England Filed: Aug. 10, 1971 Appl. No.: 170,572

Assignee:

US. Cl ..72/19 6, 72/465 Int. Cl. ..B2-1d 13/04 Field of Search ..72/i96, 465

References Cited UNITED STATES PATENTS Mowatt ..72/l96 3,191,418 6/l965 Modine ..72/i96 Primary Examiner-Lowell A. Larson Attorney-Holcombe, Wetherill & Brisebois [57] ABSTRACT A corrugation forming machine in which a sheet of material to be corrugated is passed between a pair of rollers having meshing gear-like teethQResilient means is provided either at the tip of a tooth or at the root between the adjacent teeth on the other roll with which the said tooth meshes, whereby each corrugation is pressed, as it is being formed, between the resilient means on one roll' and a relatively nonresilient portion of the other of the rolls.

6 Claims, 2 Drawing Figures This invention relates to a corrugation-forming machine, and particularly, but not exclusively to a machine for producing tube spacer strips for heat exchangers. The invention also relates to a sheet of material corrugated by such a machine and to a heat exchanger embodying such a corrugated sheet.

According to the present invention there is provided a corrugation-forming machine including a pair of coacting die rolls, each roll having gear-like teeth which mesh with the teeth of the other roll wherein each roll includes resilient means so arranged that, when a sheet of material is passed between the rolls to form corrugations in the sheet, a part of each corrugation is pressed as it is being formed'between the resilient means on one roll and a relatively non-resilient portion of the other of the rolls and corrugations are produced therein having in sequence a flank portion, a fold, a flat top portion, another fold and another flank portion.

Suitably the machine is arranged to produce corrugations in a parallel sided strip of material in which the corrugations are normal to the edges of the strip.

Conveniently a resilient means is provided at the root between each adjacent pair of teeth on at least one of the rolls and the nomresilient portion of the other roll comprises the tips of its teeth.

Alternatively a resilient means is provided at the tip of each tooth on at least one of the rolls and the non-v resilient portion of the other roll comprises the root between each adjacent pair of its teeth.

Preferably the radius of curvature of the surface of each tooth tip is greater than the mean radius of the tip from its roll axis.

Alternatively the surface of each tooth tip is formed as a grove or depression along the tip.

Conveniently each resilient means is a block of rubber-like material. I

An embodiment of the invention is described, by way of example only, with reference to the accompanying drawings in which:

FIG. 1 is a perspective scrap view of part of a heat exchanger, and

FIG. 2 is a greatly enlarged elevation of part of a' machine for making part of the heat exchanger shown in FIG. 1.

In FIG. 1 a portion of a heat exchanger consists of In FIG. 2 is shown part of a machine in which the initial operation of forming the corrugations in the tube spacer strip 11 takes place. The corrugation forming machine includes two coacting die rolls 15, 16 preferably, but not necessarily, mounted on parallel axes. Each die roll 15, 16 has meshing gear-like teeth 17 and at least one of the die rolls 15, 16 is rotated about its axis by power means.

Straight aluminum strip 18 is fed between the rolls 15, 16 so that the teeth 17 deform the strip 18 into corrugations as seen at the right hand side of FIG. 2. It will be seen that the form of the teeth 17 will be generally involute, but their profile may be somewhat modified to ensure that the gap between adjacent teeth 17 is never significantly less than the thickness of the alu- .minum strip 18.

To ensure sharp folds l2 and suitably small included angles between the tip portions 13 and the adjacent flanks 14 of the corrugations, the roots 19 between adjacent teeth 17 on each roll l5, 16 are arranged to press the aluminum strip 18 against the suitably shaped tip 20 of each co-acting tooth 17.

Between each tooth 17 there is formed a longitudinal groove 21 in which is bonded a block of rubber 22 or othersimilar material. This serves to press the aluminum strip 18 against the tip 20 of the co-acting tooth 17. The surface of each tip 20 may have a radius of curvature which is greater than the mean radius of the tip from its roll axis. Alternatively the tips 20 may be flat or even be formed as a grove or depression along each tip as shown in FIG. 2.

In an alternative construction the roots 19 between the teeth 17 may be non-resilient and profiled as required and the blocks of rubber 22 may be bonded in grooves formed along the tips 20 of the teeth 17.

If required the flank portion of each tooth 17 may be provided with slitting edges and louvre forming facets arranged normal to the folds 12 in known manner.

We claim:

1. A corrugation-forming machine, including a pair of co-acting die rolls, each roll having gear-like teeth which mesh with the teeth of the other roll and resilient means so arranged on at least one of the rolls that, when a sheet of material is passed between the rolls to 7 form corrugations in the sheet, a part of each corrugaadhesive, preferably one fold of each corrugation is tion is pressed, as it is being formed, between the resilient means on one roll and a relatively non-resilient portion of the other of the rolls.

1 2. A machine as claimed in claim 1 wherein the gear- Iike teeth are parallel to the axis of rotation of a respective roll, whereby'a parallel sided strip of material can be passed between the rolls in such a way that the corrugations are normal to the sides of the strip.

3. A machine as claimed in claim 1 wherein the resilient mean is provided at the root between adjacent teeth of at least one roll and the relatively non-resilient portion of the other roll comprises the tips of its teeth.

4. A machine as claimed in claim 1 wherein the resilient means is provided at the tip of each tooth on at least one of the rolls and the relatively non-resilient portion of the other roll comprises the root between adjacent teeth.

5. A machine as claimed in claim 1 wherein the radius of curvature of the surface of the tip of each tooth is greater than the mean radius of the tip from the axis of its roll.

6. A machine as claimed in claim 1 wherein the tip of each tooth is in the form of a groove or depression along it length. 

1. A corrugation-forming machine, including a pair of co-acting die rolls, each roll having gear-like teeth which mesh with the teeth of the other roll and resilient means so arranged on at least one of the rolls that, when a sheet of material is passed between the rolls to form corrugations in the sheet, a part of each corrugation is pressed, as it is being formed, between the resilient means on one roll and a relatively non-resilient portion of the other of the rolls.
 2. A machine as claimed in claim 1 wherein the gear-like teeth are parallel to the axis of rotation of a respective roll, whereby a parallel sided strip of material can be passed between the rolls in such a way that the corrugations are normal to the sides of the strip.
 3. A machine as claimed in claim 1 wherein the resilient mean is provided at the root between adjacent teeth of at least one roll and the relatively non-resilient portion of the other roll comprises the tips of its teeth.
 4. A machine as claimed in claim 1 wherein the resilient means is provided at the tip of each tooth on at least one of the rolls and the relatively non-resilient portion of the other roll comprises the root between adjacent teeth.
 5. A machine as claimed in claim 1 wherein the radius of curvature of the surface of the tip of each tooth is greater than the mean radius of the tip from the axis of its roll.
 6. A machine as claimed in claim 1 wherein the tip of each tooth is in the form of a groove or depression along it length. 